Abstract

The reflection dispersion relation and emission spectra of trilayerplasmonic thermal emitters with different lattice constant and Ag line width were investigated. The top Ag film is perforated with parallel line-shape hole array. The induced surface plasmons at both top and bottom interface are found coupled together. The coupling effect results in the localized surface plasmon polaritons confined at the top interface which exhibit the Fabry–Pérot resonance. The thermal emission peak position coincides with the reflection minimum in the dispersion relation and shifts to long wavelength as the Ag line width increases, which proves that the emission is due to the excitation of localized surface plasmon polaritons. Moreover, the emitted light is polarized perpendicular to the parallel metal lines.